diff --git a/dNavigation/DetourExtensions.h b/dNavigation/DetourExtensions.h
index 55d3e29cb..0610cb82e 100644
--- a/dNavigation/DetourExtensions.h
+++ b/dNavigation/DetourExtensions.h
@@ -1,5 +1,7 @@
 #pragma once
 
+#include <cstdint>
+
 #include "Recast.h"
 #include "DetourCommon.h"
 #include "DetourNavMesh.h"
@@ -9,17 +11,22 @@
 static const int NAVMESHSET_MAGIC = 'M' << 24 | 'S' << 16 | 'E' << 8 | 'T'; // char[4] of 'MSET'
 static const int NAVMESHSET_VERSION = 1;
 
+// Read straight from the .bin navmesh files
 struct NavMeshSetHeader {
-	int magic;
-	int version;
-	int numTiles;
+	int32_t magic;
+	int32_t version;
+	int32_t numTiles;
 	dtNavMeshParams params;
 };
 
 struct NavMeshTileHeader {
 	dtTileRef tileRef;
-	int dataSize;
+	int32_t dataSize;
 };
 
+// The layout the files were always read with on 64-bit builds
+static_assert(sizeof(NavMeshSetHeader) == 12 + sizeof(dtNavMeshParams));
+static_assert(sizeof(NavMeshTileHeader) == (sizeof(dtTileRef) == 8 ? 16 : 8));
+
 static const int MAX_POLYS = 256;
 static const int MAX_SMOOTH = 2048;